A color facsimile apparatus comprises a means for reading an original as color image data. According to the ITU-T recommendations, color image data is transformed into an Lab color space, JPEG-compressed, and then transmitted.
Such apparatus is expected to function as a copying machine by mounting a printer, or as an image scanner for a general-purpose information processing apparatus such as a personal computer.
In realizing this function, data must be processed in accordance with standardized color facsimile transmission. Even in printing out data or outputting it to a host computer, data must be subjected to the same color space transformation and compression. This processing is, however, more than necessary. In terms of the efficiency, there is room for improvement.
Hence, the types of color space transformation and compression are desirably switched in accordance with the intended use.
However, even if the types of color space transformation and compression are designated with a console or the like in accordance with the intended use, the most efficient processing is not always selected.